Micro-CT scouting for transmission electron microscopy of human tissue specimens

Journal Article · Mon Feb 08 00:00:00 EST 2016 · Journal of Microscopy

DOI:https://doi.org/10.1111/jmi.12385· OSTI ID:1393471

Morales, A. G. ^[1]; Stempinski, E. S. ^[1]; XIAO, X. ^[2]; Patel, A. ^[1]; Panna, A. ^[1]; Oliver, K. N. ^[1]; McShane, P. J. ^[1]; Robinson, C. ^[1]; George, A. J. ^[1]; Donahue, D. R. ^[3]; Chen, P. ^[1]; Wen, H. ^[1]

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1. National Inst. of Health (NIH), Bethesda, MD (United States). National Heart Lung and Blood Inst.
2. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
3. National Inst. of Health (NIH), Bethesda, MD (United States). National Inst. of Neurological Disorders and Stroke

Transmission electron microscopy (TEM) provides sub-nanometre-scale details in volumetric samples. Samples such as pathology tissue specimens are often stained with a metal element to enhance contrast, which makes them opaque to optical microscopes. As a result, it can be a lengthy procedure to find the region of interest inside a sample through sectioning. Here, we describe micro-CT scouting for TEM that allows noninvasive identification of regions of interest within a block sample to guide the sectioning step. In a tissue pathology study, a bench-top micro-CT scanner with 10 m resolution was used to determine the location of patches of the mucous membrane in osmium-stained human nasal scraping samples. Furthermore, once the regions of interest were located, the sample block was sectioned to expose that location, followed by ultra-thin sectioning and TEM to inspect the internal structure of the cilia of the membrane epithelial cells with nanometre resolution. This method substantially reduced the time and labour of the search process from typically 20 sections for light microscopy to three sections with no added sample preparation. Lay description Electron microscopy provides very high levels of detail in a small area, and thus the question of where to look in an opaque sample, such as a stained tissue specimen, needs to be answered by sectioning the sample in small steps and examining the sections under a light microscope, until the region of interest is found. The search process can be lengthy and labor intensive, especially for a study involving a large number of samples. Small areas of interest can be missed in the process if not enough regions are examined. We also describe a method to directly locate the region of interest within a whole sample using micro-CT imaging, bypassing the need of blindly sectioning. Micro-CT enables locating the region within 3D space; this information provides a guide for sectioning the sample to expose that precise location for high resolution electron microscopy imaging. In a human tissue specimen study, this method considerably reduced the time and labor of the search process.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1393471
• Journal Information: Journal of Microscopy, Journal Name: Journal of Microscopy Journal Issue: 1 Vol. 263; ISSN 0022-2720
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
bench-top micro-CT scanner
micro-CT scouting
three-dimensional visualization
transmission electron microscopy